Temporal: Improve existing tests for ZDT#toString timeZoneName option

Based on the improvements just made to the calendarName option, improve
the tests for the timeZoneName option of ZonedDateTime.prototype.toString
as well.

test/built-ins/Temporal/ZonedDateTime/prototype/toString/timezonename-auto.js

@@ -0,0 +1,23 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.tostring
+description: If timeZoneName is "auto", the time zone ID should be included.
+features: [Temporal]
+---*/
+
+const tests = [
+  ["UTC", "1970-01-01T01:01:01.987654321+00:00[UTC]", "built-in UTC"],
+  ["+01:00", "1970-01-01T02:01:01.987654321+01:00[+01:00]", "built-in offset"],
+  [{
+    getOffsetNanosecondsFor() { return 0; },
+    toString() { return "Etc/Custom"; },
+  }, "1970-01-01T01:01:01.987654321+00:00[Etc/Custom]", "custom"],
+];
+
+for (const [timeZone, expected, description] of tests) {
+  const date = new Temporal.ZonedDateTime(3661_987_654_321n, timeZone);
+  const result = date.toString({ timeZoneName: "auto" });
+  assert.sameValue(result, expected, `${description} time zone for timeZoneName = auto`);
+}

test/built-ins/Temporal/ZonedDateTime/prototype/toString/timezonename-invalid-string.js

@@ -15,4 +15,12 @@ features: [Temporal]
 ---*/
 
 const datetime = new Temporal.ZonedDateTime(1_000_000_000_987_64_321n, "UTC");
-assert.throws(RangeError, () => datetime.toString({ timeZoneName: "other string" }));
+const invalidValues = ["NEVER", "sometimes", "other string", "auto\0"];
+
+for (const timeZoneName of invalidValues) {
+  assert.throws(
+    RangeError,
+    () => datetime.toString({ timeZoneName }),
+    `${timeZoneName} is an invalid value for timeZoneName option`
+  );
+}

test/built-ins/Temporal/ZonedDateTime/prototype/toString/timezonename-never.js

@@ -0,0 +1,23 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.tostring
+description: If timeZoneName is "never", the time zone ID should be omitted.
+features: [Temporal]
+---*/
+
+const tests = [
+  ["UTC", "1970-01-01T01:01:01.987654321+00:00", "built-in UTC"],
+  ["+01:00", "1970-01-01T02:01:01.987654321+01:00", "built-in offset"],
+  [{
+    getOffsetNanosecondsFor() { return 0; },
+    toString() { return "Etc/Custom"; },
+  }, "1970-01-01T01:01:01.987654321+00:00", "custom"],
+];
+
+for (const [timeZone, expected, description] of tests) {
+  const date = new Temporal.ZonedDateTime(3661_987_654_321n, timeZone);
+  const result = date.toString({ timeZoneName: "never" });
+  assert.sameValue(result, expected, `${description} time zone for timeZoneName = never`);
+}

test/built-ins/Temporal/ZonedDateTime/prototype/toString/timezonename-undefined.js

@@ -19,4 +19,4 @@ const datetime = new Temporal.ZonedDateTime(1_000_000_000_987_654_321n, "UTC");
 const explicit = datetime.toString({ timeZoneName: undefined });
 assert.sameValue(explicit, "2001-09-09T01:46:40.987654321+00:00[UTC]", "default timeZoneName option is auto");
 
-// See options-undefined.js for {}
+// See options-object.js for {} and options-undefined.js for absent

test/staging/Temporal/ZonedDateTime/old/toString.js

@@ -11,12 +11,6 @@ features: [Temporal]
 var zdt1 = Temporal.ZonedDateTime.from("1976-11-18T15:23+00:00[UTC]");
 var fakeGregorian = { toString() { return "gregory" }};
 
-// shows time zone if timeZoneName = auto
-assert.sameValue(zdt1.toString({ timeZoneName: "auto" }), "1976-11-18T15:23:00+00:00[UTC]");
-
-// omits time zone if timeZoneName = never
-assert.sameValue(zdt1.toString({ timeZoneName: "never" }), "1976-11-18T15:23:00+00:00");
-
 // shows offset if offset = auto
 assert.sameValue(zdt1.toString({ offset: "auto" }), "1976-11-18T15:23:00+00:00[UTC]");